Birthmarked (Birthmarked Trilogy, 1)

In the future, in a world baked dry by the harsh sun, there are those who live inside the wall and those, like sixteen-year-old midwife, Gaia Stone, who live outside. Gaia has always believed it is her duty, with her mother, to hand over a small quota of babies to the Enclave. But when Gaia's mother and father are arrested by the very people they so dutifully serve, Gaia is forced to question everything she has been taught to believe. Gaia's choice is now simple: enter the world of the Enclave to rescue her parents, or die trying.